1099-MISC

Yes. Some 1099-MISC issuers only have one Tax ID, which is used for both federal and state. If the State ID in box 17 is blank, you can leave it blank on the system. If it asks you to input some information there, you can use the Payers TIN or EIN.

If Box 17 is blank do I still need to report what is in Box 18 (Box 18 has a dollar amount which is the same as what is in Box 3)?

Yes, box 18 is for the amount to be enter for your state income.  Since the income amount for the state can differ, you will want to enter the amount in the 1099-MISC entry.  If this is not entered, it could be transferred over to your state return incorrectly.  

@earl28